Maltego - Maltego is an open source intelligence and forensics application.
Sherlock - Sherlock provides insights on user engagement for product makers.
OSINT Tool - OSINT-tool.com is two things.
Userlane - Digital adoption platform with interactive guidance for software applications allowing anyone to understand and master any software from the get-go.
SpiderFoot - Open source intelligence (OSINT) automation tool.
UserGuiding - User onboarding made easy, for less. Create product walkthroughs in a couple of clicks, without breaking the bank.